B3310

e coli protein expression

for protein expression and DNA plasmid production

• Synonym(s): BL21 Competent Cells, BL21 (DE3)pLysS-T1^R Competent Cells
• MDL number: MFCD01634471
• UNSPSC Code: 12352200

Properties

• grade: for molecular biology
• form: suspension
• shipped in: dry ice
• storage temp.: −70°C

Description

General description

BL21(DE3)pLysS-T1^R are competent E. coli that are suitable for high level induction and expression genes regulated by expression vectors with T7 promoter. The cells have transformation efficiency of ≥5x10⁶ cfu/μg when transformed with non-saturating amounts of pUC19 plasmid DNA.

Sigma′s BL21-T1^R competent E. coli cells are grown and made chemically competent using an optimized procedure specific to the strain, followed by strain verification and efficiency testing. The cells are provided in frozen 50 μl aliquots for convenience. Each aliquot can be used for a single transformation.

Application

Suitable for induction and expression of genes directed by the expression systems with T7 promoter

Features and Benefits

• Ensures induction and expression of genes from any T7-promoter based expression system
• Contains the genotype tonA that protects the clonal stocks from lytic bacteriophages
• Contains T7 RNA polymerase that is inducible by addition of IPTG to the culture
• Renders resistance to chloramphenicol; useful for selection process
• Allows compatibility with plasmids containing ColE1 or pMB1 origin
• Guaranteed high transformation efficiency
• Convenient 50 μL aliquots

Components

• BL21(DE3)pLysS-T1^R chemically competent cells, 10 X 50 μL (B3185)
• pUC 19 control DNA (10 ng/μL), 10 μL (D2567)

Principle

BL21(DE3)pLysS-T1^R does not express ion proteases and outer membrane protease, ompT. This prevents the degradation of heterologous proteins expressed by T7 expression vector systems. This strain also contains tonA genotype that confers resistance to lytic bacteriophages such as T1 and T5. The strain is lysogenic for lambda prophage and contains an inducible T7 RNA polymerase regulated by lacUV5 promoter. T7 lysozyme produced by the pLysS plasmid inhibits T7 polymerase that improves transcriptional control.

Safety Information

• Storage Class Code: 10 - Combustible liquids
• Flash Point(F): Not applicable
• Flash Point(C): Not applicable